Structural steel drill



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H16 ATTORNEY June 18, 1963 MEAD 3,094,015

STRUCTURAL STEEL DRILL Filed Aug. 11, 1960 6 Sheets-Sheet 6 INVEN TOR. EDW/NL. MEAD United States Patent O 3,094,015 STRUCTURAL STEEL DRILL Edwin L. Mead, Pittsburgh, Pa., assignor to Mulfah Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Aug. 11, 1960, Ser. No. 48,926 12 Claims. (Cl. 77-21) This invention relates generally to machine tools and more particularly to a production machine for performing operations on long workpieces such as structural steel.

This machine tool is particularly adapted for use in a production line for drilling holes in structural steel. One of the principal problems in work of this character is the measuring and boring of the holes in structural steel which is ordinarily done by skilled artisans with rules and chalk or templates. After the position of the holes are located, they are either punch-spoted to provide a lead for drilling, are drilled by hand, or moved through a drill press which requires the movement and re-spotting of each hole or group of holes all the Way along the workplece.

This necessitates a repeated moving of the heavy structural steel and frequently results in errors not only due to a mis-spoting of the hole markings, but also a misspoting of the markings in the drilling.

The principal object of the invention is the provision of a machine tool having a datum point for one end of the workpiece and from which all the measurements longitudinally of the workpiece are made. This requires a table to receive the workpiece and a means to hold the workpiece at the datum point, together with a carriage capable of operation along the workpiece from this datum point. Thus, the workpiece is held stationary and the tools travel therealong.

Another object of this invention is the provision of a gauge means for locating the tools relative to the side face of the workpiece for accurately locating the tool operation, regardless of any curvature in the long workpiece.

Another object of this invention is the provision of a gauge means relative to the top face of the work piece to compensate for any inaccuracies in the structural member relative to the horizontal plane in which the workpiece is disposed. Thus, a tool operation such as drilling may be accurately located relative to the web or an I-beam or channel when the holes are being drilled in the flanges.

This invention lends itself to more accurately locate drilled holes along the Web flanges of structural members regardless of their twist or curvature which may be later removed from the beam or when the beam is inserted in position may be straightened or compensated for when secured to its adjacent parts by riveting or bolting.

Thus, the problems of inaccurate location of the holes which are apt to have considerable human error, together with the inaccurate supporting of the holes after they have been located by punch, and the difliculty of locating the holes in a slightly curved or twisted beam, are all overcome by this improved machine tool.

In structural steel the size and location of the holes in the different beam members are more or less uniform. Thus, the drill members can be preset and rapidly moved by a carriage from one position to another for drilling a repeated series of holes along the beam with a very high degree of accuracy and under considerably improved production technique over that previously employed.

Another object of this invention is the provision of ,a traveling carriage for a machine tool that is capable initially of conveying and positioning the workpiece at a datum point and thereafter locating and performing work operations on the workpiece in rapid succession with a very high degree of accuracy. The carriage is not only capable of moving the workpiece and locating 3,094,015 Patented June 18, 1963 the same, but is provided with a clamp means to hold the workpiece at each work operating position along the workpiece together with a gauge means to gauge it from both the vertical and horizontal planes.

Other objects and advantages appear hereinafter the following description and claims.

The accompanying drawings show for the purpose of exemplification without limiting the invention or claims thereto, certain practical embodiments illustrating the principles of this invention wherein:

FIG. 1 is a schematic plan view of the drilling machine showing the .feed and discharge conveyors.

FIG. 2 is a plan view of the drilling machine showing the tracks, table, and the gantry.

FIG. 3 is a view in side elevation of the work-holding datum magnet.

FIG. 4 is a transverse sectional view taken on the line 4-4 of FIG. 2.

FIG. 5 is a transverse sectional view taken on the line 55 of FIG. 2.

FIG. 6 is a view in side elevation of the traveling gantry with parts in section showing a horizontal locating device for positioning the horizontal drill-s relative to one side of the workpiece.

FIG. 7 is a view in end elevation of the gantry shown in FIG. 6 with parts in section.

FIG. 8 is a view in side elevation of the gantry having a vertical locating device for the horizontal drills relative to a horizontal portion of the workpiece.

FIG. 9 is a plan view of the structure shown in FIG. 8.

' FIG. 10 is view in end elevation of the structure shown in FIG. 9.

FIG. 11 is a perspective view showing a workpiece about to be drilled.

FIG. 12 is a perspective view showing the gantry adjacent the holding magnet.

FIG. 13 is a perspective view of the front of the machine together with the operating station and a workpiece in position.

Referring to FIG. 1 the machine tool comprising this invention is illustrated schematically by the table 1 which has the main carriage or gantry 2 movable therealong. The table 1 should be sufficiently long to accommodate the longest structure or workpiece employed in the structural fabrication. The structural steel parts are cut to size and are transferred laterally to the transfer table 3 and onto the conveyor 4. The transfer table 3 may be provided with suitable conveyor chains or walking lbeam conveyor structure to laterally move the workpiece onto the conveyor 4, which moves the workpiece longitudinally until it arrives onto the table 1, from whence it is engaged by the gantry clamping means and travelled to the datum point 5 where the end of the workpiece is secured and from which all measurements are determined. The gantry is usually moved to the first operating position which is adjacent the datum point 5 and performs suc- 'cessive drilling operations therefrom. As soon as the drilling operation of each position is completed, the gantry is unclamped and moved to the necessary succeeding point along the Workpiece'and so on until it has completed the drilling operation after which the work-piece is released at the datum point 5 and the gantry clamp then engages the workpiece to move it longitudinally onto the conveyor 6, from whence it is moved laterally to the transfer table which can function as a storage table. When the workpieces are again needed, they are transferred to the conveyor 8 which travels the workpiece to further storage or shipping lines or the fabrication department.

As shown in FIG. 2 the machine tool comprising this invention includes the table 1 and the drilling gantry 2. The table 1 consists of a base which is constructed of a series of spaced piers 11 on which are mounted the parallel I-bearns 12 and 13 that are connected transversely by the cross-tie beams 14.

Inverted channel members 15 are secured on the top of each of the I-beams 12 and 13 and are provided with longitudinally disposed rails 16 that form a track on which the gantry 2 travels. The rails 16 are held in place by cleats as shown. On the inside of the channel members 15, a depending member 17 forms a box with the channel members and helps to support them relative to each of the cross-tie beams 14. On the face of the plates 17 are mounted the racks 18 which are engaged by suitable power-driven pinions for traversing the gantry 2 along the track 16. A hand wheel may be connected to the pinions by a clutch for the purpose of making increment manual adjustment of the gantry along the workpiece.

Between the rails 16 the base 10 is provided with a pair of spaced I-beams 20 and 21 that extend longitudinally for the full length of the base to provide a table structure and are secured to the cross-tie beams 14. A floor plate 22 connects the top of the I-beams 20 and 2-1 to produce the table surface and at spaced intervals cross-tie members 23 are secured at their ends to I-beams 20 and 21. These transverse members 23 are preferably supported directly below the spaced bearing stands 24 which support the shaft 25 for rotation on which is mounted the space rollers 26. The space rollers 26 are in the form of spools as illustrated for receiving the workpiece. If the workpiece is an I beam, the web is usually laid horizontally and the lower flanges ride along the spool rollers 26. As shown in FIG. 2, the space rollers 26 are mounted on the shaft 25 with considerable spacing therebetween. The adjustment between these rollers is made to accommodate the I or H beams or channel members having the greatest web depth. If the I or H beam has a web which is of relatively small depth, then the spool rollers 26 are positioned relatively close to each other on the shafts 25 as illustrated in FIG. 5. Thus, spool rollers 26 are readily positioned to accommodate different steel structures. The gantry 2 is provided with an operator station as indicated at 27 and is provided with a viewer 28 which includes an opti cal magnifying means to allow him to see very clearly the tape indicated at 30 that is secured to one face of the inverted angle iron 31 which in turn is mounted on the brackets 32 which extend from the I beam 20 as illustrated in FIG. 5. The tape 30 extends from the datum point 5 and indicates to the operator the exact location of the tools on drills carried by the gantry. This reference may be for the first drill or any one of the drills in the group and when the tape is viewed through the optical device 28, it will always provide a direct reading on the location of the reference drill along the track or the workpiece supported by the spool rollers 26. The optical device 28 not only magnifies the reading on the tape, but also provides a hair line so that the reference drill can be accurately located within a small fraction of an inch and with the aid of vernier, a more accurate location can be made.

Rather than to rely upon the human error in reading the tape, this tape may be of course provided with a code which will accurately locate the gantry at any desired position along the track through the use of photoelectric devices or wiping contactors or any other suitable means.

The datum point 5 is shown to be provided with an electromagnet 33 which positions with its magnetic face 34 at the exact datum point. The steel workpiece would be moved along the idler space rollers 26 until it engages the face 34 when in its extended position, and when the electromagnet 33 is energized each workpiece will be held tightly thereagainst to provide a datum point for all references in performing drilling or other similar machine tool operations along the workpieces. The electromagnet 33 is held in the carriage 35 for movement vertically in the ways 36, the carriage 35 being provided with the rollers 37 that operate in the ways 36 and as shown in FIG. 4. The carriage 35 is actuated by the air cylinder or the pneumatic jack 40 which comprises the cylinder mounted on the base'41 and having an extensible piston secured to the carriage 35. Thus when the cylinder is energized the piston forces the carriage 35 vertically until the face of the electromagnet 33 reaches the position illustrated in FIG. 3 in full lines. Thus, when the gantry has completed its operations on the workpiece, the electromagnet 33 may be de-energized and withdrawn to the position shown in FIG. 4 to permit the workpiece to continue onward to the conveyor 6.

The inverted channel 15 as shown in FIG. 5 mounted on the I-beams 12 and 13 may conveniently provide a canopy to cover the electrical trolley wires 38 for feeding electric current to the gantry as it moves along the table *1 in the manner similar to that of a crane.

As illustrated in FIG. 6 and FIG. 7, the gantry 2 is formed with two 0 members 42 and 43 tied together and secured to each other by the cross members 44, 45, and 46. Each 0 member has a central flange 47 and outer and inner face members 48 and 49, both of which define the inner and outer surfaces of the C. The outer face members 48 are rounded at the corners as indicated in FIG. 6 and are connected together by an intermediate casing 59. This structural arrangement of the gantry is unique in that it provides ample space enclosed by the face plates 51 for housing relays, control members and all the other apparatus necessary to operate the gantry and the work tools that it carries. -In FIG. 6 the face plate has been removed to more readily disclose the drills supported by the gantry.

The leg of each of the 0 members provides a bearing 52 therein for supporting the lipped rollers or wheels 53, that ride along the rails 16. Thus, four wheels are provided for supporting the gantry.

As shown in FIGS. 6 and 7, the 0 members 42 and 43 making up the gantry each have the angle members 54 secured on their inner face as illustrated in FIG. 7, and the opposed faces of these angle members 54 support the rail members 55 and 56 between which ride the rollers 57 mounted on the outer carriage 58. The outer carriage 58 thus travels between the 0 members 42 and 43 and transversely of the gantry. The carriage is operable between the transverse members 46.

The outer carriage 58 has depending from the side opposite operators position 27 a gauge arm 60. This gauge arm is secured to the inner face of one end of the carriage 58 by means of the bolts 61. The carriage arm is a structural member made with three faces having holes therein to lighten the weight of the material on the carriage and also provide a web between each of the three faces to produce a strong arm. The lower end of which is bifurcated as shown in FIG. 6 and provided with the space pads 62 along which the roller bracket or support 63 is adjustable. Each roller bracket rotatably supports the roller 64 on a vertical pin 65 so as to engage outer face 66 of the flange on the workpiece illustrated in FIG. 6. The carriage 58 is actuated by air cylinder 67, the piston 68 of which is secured to one end of the carriage 58. The air cylinder holds the carriage 58 at all times with the roller 64 engaging the flange face 66 of the workpiece. Frequently, a very long beam will have a bow in it. This how may be slight, but nevertheless if not taken into account, it will cause an inaccurate location in the vertically drilled holes through the web. Here the rollers 64 are constantly held against the face 66 of the workpiece to continuously locate the vertical drills 70 at the proper position relative to the flange face 66 of the workpiece.

The vertical drill 70 of which there are three in alignment shown in a single holder are all driven in unison by the motor 71 operating through the gear reducer 72 mounted in the diamond-shaped carriage 73. This carriage comprises opposed diamond-shaped plates connected by the transverse members 74 and 75 and the tube 76.

A gear reducer 72 supports the motor 71 through the bracket '77 mounted on the casing of the gear reducer. The gear reducer is in turn secured to the transverse member 74 and may be bolted in adjusted positions up or down the face of transverse member 74. The drill head 78 is adjustably positioned relative to the gear reducer 72 by means of the slides 80 operable to feed the drills 70 downwardly when actuated by the pneumatic cylinder. The slides 80 operate through the guides 81 for feeding the drill during the drill operation.

The diamond-shaped inner carriage is suspended by the three rollers 82, 83, and 84 of which rollers 82 and 83 ride along the lower track 85 and the rollers 84 ride along the upper track 86. Each of the upper tracks 86 support a rack member 87 engaged by its respective pinion 88 secured to the shaft 89 operated by the hand wheel 90. Intermediate of its ends the shaft 89 is journaled in the diamond-shaped inner carriage 73. Plates 75 of the-inner carriage 73 support a transverse operated brake mechanism 91 that functions to operate the brake shoes 92 on wheel 93 secured to shaft 89. Thus once the inner carriage 73 is located relative to the outer carriage 58, power operated mechanism 91 of the brake may be energized to lock the shaft 89 and thus fix the position of the drills 70 relative to the carriage 58. In place of the hand wheel, a remote control motor 94 may be employed to operate the pinion 95 that meshes with one of the pinions 88 for governing the movement of the inner carriage 73 within the outer carriage 58.

Ordinarily the web of the workpiece requires only three holes from the drill 70 and these holes are fixed relative to the face 66 of the workpiece. Thus the inner carriage 73 would not have been adjusted relative to outer carriage 58 at each drilling position along the work piece. If on the other hand the web is of considerable depth, six or even a greater number of holes are required at each point which would necessitate the movement of the inner earriage 73 relative to the outer carriage 58 for the purpose of drilling the holes along the full depth of the web.

Only a set of three drills are shown at 70 and these drills are thus located by the carriage arm '60 relative to the face 66 of the workpiece. However, any number of holes may be employed and a different pattern or arrangement of the drills can be made by changing the head 78, so as to dispose the drills in a sloping or triangular arrangement relative to each other.

The horizontal drills 96 of which there are two in each head 97 and 98 respectively on opposite legs of the C-shaped gantry 2 are supported for movement horizontally on the basket 1% and 101 which slidably support their gear reducing mechanism 102 driven by their respective motors 103. The drill head is reciprocally supported on the guides 184 being fed horizontally toward the opposite flange faces of the I-beam workpiece to drill the flanges. The drills 96 may be adjustably spaced relative to each other by changing the heads 97 and 9 8 as shown in FIG. 6. These drills are leveled so as to drill holes in alignment with each other in the opposite flanges equidistant from the web of the workpiece. This alignment is obtained by making each of the baskets 100 and 101 adjustable vertically relative to the workpiece. As shown, there are two sets of vertical tracks in the opposite legs of the C members 42 and 43 as illustrated at 105 and 4106-. These track members receive the rollers 167 which support their respective baskets for vertical movement within the gantry. As shown in FIGS. 8 and each basket 100 and 18-1 are suspended by a pair of rack members 108 which are pivotal-1y connected to each side of each basket 109' and 101 which each rack member pass upwardly through bearings 110 and are engaged by their respective worm gears 111 on the shafts :1 12 which are also journaled in the bearings 110. Since one suspension rack 10 8 is on each side of each basket, it is necessary to duplicate the operating structure on opposite sides of the gantry as indicated in FIGS. 9 and 10. Each shaft 112 carries a sprocket gear 113 and these sprocket gears are connected together by a chain 114. Thus the operation of one shaft 112 as by the handwheel :115 operates both shafts 112 in unison to raise or lower the baskets 100 and 101. Each shaft 112 is provided with a rack-supported bearing 11 6 to carry the rack member 117 that engages a gear on the shafts 112 to raise and lower the shafts 112 due to the elevation of the roller 118 that rides against the top web surface of the I beam workpiece on the table. These racks are connected to the shafts 112 in the same manner as the other rack 188. The whole of this system is biased so as to provide a pressure through the wheels 11% against the beam .web to lower the baskets 100 and 101. Counterweights 120 are within the gantry 2 to balance the weight of the baskets so that a few pounds pressure is applied by the rollers 118 to thereby maintain the baskets 109 and 181 in their proper vertical position to hold the drills 96 equidistant from the center line of the workpiece on the web.

As shown in FIG. 9 the electromagnetic brake 121 is mounted on one of the shafts 112 to lock the mechanism at its adjusted position and prior to the time that the drills are fed horizontally into the workpiece. Although a servomotor may be employed to feed the drills of the workpiece they may also be fed by the handwheel 122 as shown in PEG. 7.

As shown in FIGS. 2, 11 and 12, each 6 member of the gantry 2 is provided with a rotary mounted screw 123 journale-d in the bearing supports 124- and provided with a right and left-hand screw section 125- and 126. Each screw thread section is provided with a nut 127 and 128 for the purpose of actuating the clamping jaws 129 and 130 respectively. Thus four clamp jaws are provided on the gantry and are operated by the rotary screw members 123' which are driven through a clutch 131 by a motor 132' so as to tightly grasp the workpiece on opposite sides thereof and on opposite sides of vertical and horizontal drills to center and rigidly clamp the workpiece relative to the gantry at each operating position. When the motor 132 is rotated to drive the screws 123, the clamp jaws are forced tightly against the workpiece to grip the same and retain the tension of this grip until the clutch slips. The motor may then be shut off by a limit control switch and the pressure of the thread of the screws will retain this grip by the jaws. Another rnode of retaining the grip is by continuing to allow the motor to be energized and permitting the clutch to s-li' The weight of the clamping jaws need not be carried by the screws 123 as these jaw members may be suspended from the track 133 formed between the two sets of channels 134 that bridge between the legs of each C forming a gantry and in F168. l0, l2 and 13 which show the opposite side of the gantry.

As shown in FIG. 2 a platform 135 is provided for the operators station 27 and a complete control panel 136 is provided with all of the control switches for controlling each of the operations described, such as extension and retraction of the datum point 5, together with the deenergization of the magnet therein. The unlocking and locking of each of the shafts in the systems provided properly adjust the horizontal and vertical drills.

The gantry is provided .with a vertical motor shaft 137 that carries a pinion 138 at the lower end to engage on the racks 18 for the purpose of traversing the gantry from one end of the table 1 to the other. In this way the operator may energize gripping jaws 129 and 130 to engage the workpiece and carry it to any position along the work table 1 over the idler rollers 26 or to feed the workpiece onto the table or ofi the table 1. The vertical shaft 137 is also provided with a handwheel 139 to permit the operator to make close adjustments in positioning the gantry along the workpiece.

As shown in FIG. 12 a compressor and tank 140 is mounted on the gantry for the purpose of supplying each of the pneumatic driven servomotors or cylinders.

Each of the drill heads is provided with an offset stop 99 which engages the face of the work when the drilling operation has been completed and prevents further movement of the drill head relative to the work. A switch actuated by pressure on this stop will function to reverse the motion of the drilling head and retract the drills to their inoperative position.

1 claim:

1. A machine tool comprising a table having a longitudinally extending conveyor thereon to support and carry the work, a gantry supported for movement along said table, a work vise carried by said gantry for engaging the work to move it along said conveyor and hold the gantry relative to the work while operations are performed thereon, a datum point on said table, lock means to engage and hold the work with reference to said datum point, and work-operating means carried by said gantry to perform operations at consecutive positions along the work with reference to said datum point.

2. The machine tool of claim .1 characterized by control means to actuate said work vise and hold the gantry relative to the work during the operation of said Work operating means at each consecutive position along the work.

3. The machine tool of claim 1 charatcerized in that said work vise comprises jaw means that engage the opposite sides of the workpiece to center the same relative to said gantry.

4. The machine tool of claim 1 characterized in that said work vise comprises two sets of jaw means that engage the opposite sides of the workpiece and on opposite sides of the work-operating means.

5. The machine tool of claim 1 characterized in that said Work vise includes jaws engaging the opposite sides of the workpiece and screw means with threads of opposite hand connected to actuate said jaws to center the work relative to the gantry.

6. The machine tool of claim 1 characterized in that said gantry is in the form of a bridge, parallel rails on each side of said table, wheels on said bridge to carry it along said table over the work when said work vise is not actuated.

7. The machine tool of claim 6 characterized by power means to move said gantry along said tnack.

8. The machine tool of claim 6 which also includes a hand wheel to move said gantry, along said track, and said work vise holding said gantry relative to the work.

9. The machine tool of claim 1 characterized by a tape extending parallel with said table, a viewer carried by said gantry to observe said tape and an indicator in said viewer to co-operate with said tape to position said operating means relative to said datum point by the movement of said gantry along said table.

10. The machine tool of claim 1 characterized in that said lock means is a retractable clamp means, and power means to extend and retract said clamp means from the path of the Work.

11. The machine tool of claim 10 characterized in that said clam-p means is an electro-magnet, a carriage supporting said magnet and reciprocated by said power means.

12. A machine tool for elongated work consisting of a stationary table, a work supporting conveyor on said table, a datum point on said table, lock means to engage and hold said work relative to said table with reference to said datum point, a gantry supported for movement along said table and said work conveyor, Work tools carried by said gantry, a work vise carried by said gantry to engage and hold said gantry relative to said work while said work tools perform their operations thereon.

References Cited in the file of this patent UNITED STATES PATENTS 11,241,247 Payne Sept. 25, 1917 1,702,370 Trevellyan et al Feb. 19, 1929 2,947,203 Ausenda et a1 Aug. 2, 1960 2,974,548 Miller Mar. 14, 1961 FOREIGN PATENTS 143,726 Australia Oct. 9, 1951 

1. A MACHINE TOOL COMPRISING A TABLE HAVING A LONGITUDINALLY EXTENDING CONVEYOR THEREON TO SUPPORT AND CARRY THE WORK, A GANTRY SUPPORTED FOR MOVEMENT ALONG SAID TABLE, A WORK VISE CARRIED BY SAID GANTRY FOR ENGAGING THE WORK TO MOVE IT ALONG SAID CONVEYOR AND HOLD THE GANTRY RELATIVE TO THE WORK WHILE OPERATIONS ARE PERFORMED THEREON, A DATUM POINT ON SAID TABLE, LOCK MEANS TO ENGAGE AND HOLD THE WORK WITH REFERENCE TO SAID DATUM POINT, AND WORK-OPERATING MEANS CARRIED BY SAID GANTRY TO PERFORM OPERATIONS AT CONSECUTIVE POSITIONS ALONG THE WORK WITH REFERENCE TO SAID DATUM POINT. 